And yet, despite the lack of water, many animals found in its dunes exhibit adaptations similar to those found in aquatic organisms. The fine sands of the desert have remarkably liquid-like physical properties, forcing the development of various kinds of “swimming”, “surfing”, and “diving” behaviors.
Last year I briefly visited Sussusvlei in the Namib, a place famous for its enormous, bright red and orange dunes. There I found an animal that exemplifies many characteristics of desert “swimmers.” Splay-footed cricket (Comicus capensis) is a member of the family Schizodactylidae, a strange lineage of the Orthoptera, found only in a few places of southern Africa and southwestern Asia. Morphologically these insects have remained virtually unchanged sine the Early Cretaceous, over 100 million years ago.
Their common name is derived from the shape of their feet, each of which has four long “fingers” that greatly expand the foot’s surface area, turning them into “paddles” that allow the insect to run and “swim” in the sand. So effective are these paddles that it took me almost 10 minutes to capture this tiny, 15 mm long animal, as it jumped and zipped through the sand. Splay-footed crickets are predators, actively chasing and devouring other small desert invertebrates, but otherwise little is known about their biology.